US4467583A

US4467583A - Reinforcement basket for reinforced-concrete column

Info

Publication number: US4467583A
Application number: US06/411,110
Authority: US
Inventors: Wilhelm Hasak
Original assignee: LANDSHUTER BAUEISENBIEGEREI GmbH
Current assignee: BTH BIEGETECHNIK HASAK GmbH
Priority date: 1980-01-09
Filing date: 1982-08-24
Publication date: 1984-08-28
Anticipated expiration: 2001-08-28
Also published as: CH655750A5; AT380712B; DE3000605A1; DE3000605C2; ATA533580A; US4377928A

Abstract

A reinforced-concrete column reinforcement comprises at least two hoops centered on and spaced apart along an axis and a plurality of deformable holders fixed at angular spacings on these hoops. Respective longitudinal reinforcement bars each extend axially through one of the holders of one of the hoops and through a respective one of the holders of the other of the hoops. The holders grip these bars. A helicoidal wrapping wire generally centered on the axis is welded to axially extending spacer rods fixed to the hoops and surrounds these rods and the reinforcement bars. The holders may be constituted as malleable metal elements welded on the hoops and forming passages through which the reinforcement bars pass. Once these reinforcement bars are fitted through the passages these elements may be deformed into tight clenching contact with the bars.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application is a division of copending patent application Ser. No. 190,170 filed Sept. 23, 1980, now U.S. Pat. No. 4,377,928.

FIELD OF THE INVENTION

The present invention relates to a reinforced-concrete column. More particularly this invention concerns a so-called reinforcement basket formed of steel bars and wires that is embedded in such a column.

BACKGROUND OF THE INVENTION

A reinforcement for a reinforced-concrete column normally consists of a plurality of hoops centered on and spaced apart along the longitudinal axis of the column to be produced, and a plurality of longitudinally extending reinforcement bars secured to these hoops. A helical wire wrap surrounds the longitudinal reinforcement bars. The reinforcement bars have to be secured to the hoops at their intersections, and the wire wrap is secured to some of these bars and to the hoops.

As the size of such a reinforcement basket is relatively large, standard practice is to fabricate it on the job. The most preferred practice is to weld the arrangement together, which requires the use of weldable steel such as so-called IIIb ribbed steel bar for concrete reinforcement. This material is relatively expensive and frequently hard to obtain on short notice.

Thus it is standard practice to resort to the use of cheaper nonweldable steel bars, that is bars which cannot readily be welded to the hoops. A connection is therefore made by looping wire around the intersections of the reinforcement bars and the hoops. This is a relatively labor-intensive process which, unfortunately, still does not ensure good positioning of the various elements relative to each other. Frequently when such a prefabricated basket is being lifted into place it deforms somewhat, requiring it to be painstakingly reworked.

OBJECTS OF THE INVENTION

It is therefore an object of the present invention to provide an improved reinforcement for a reinforced-concrete column.

Another object is to provide such a reinforcement which allows relatively easy on-the-job assembly of a reinforcement basket.

A further object is to provide such a reinforcement which uses relatively inexpensive and easy-to-obtain steel reinforcement bars of the type that can normally not be welded.

SUMMARY OF THE INVENTION

These objects are attained according to the instant invention by securing longitudinal reinforcement bars to the hoops by means of deformable holders which are permanently fixed at angular spacings on the hoops. These holders are deformed around the longitudinal reinforcement bars to hold them in place. A helicoidal wrapping wire generally centered on the axis of the assembly is fixed to the hoops and surrounds the bars.

Thus with the system according to the instant invention the longitudinal reinforcement bars are fitted to the holders on the hoops and then the holders are deformed tightly around them, normally by simply striking them with a hammer to bend them into tight contact with the reinforcement bars. The result is an extremely solid connection which can be produced very quickly and, therefore, at very low labor cost. The holders themselves are provided on the reinforcement bars and can easily be mass-produced at low cost.

The wrapping wire is fixed, normally by welding, to axially extending spacer rods which themselves are normally fixed to the hoops by welding. Thus these spacer rods and the wrap wire ensure proper positioning of the various elements of the reinforcement basket to each other. The resultant reinforcement rod, therefore, is extremely strong, yet very easy to assembly.

According to further features of this invention each of the holders has a malleable metal element forming an axially through-going passage through which the respective reinforcement bar passes. These elements may be generally U-shaped, having one leg welded to the respective hoop and another leg spaced from the respective hoop. This other leg may be formed with a bumper barb for securing the respective longitudinal reinforcement bar in place, and may also be formed with a weakened region so that it can be bent over around the respective longitudinal reinforcement bar. In addition the elements may be formed as eyes which are bent closed after the reinforcement bars are inserted through them. Two short upstanding pins may be provided between which the reinforcement bar is fitted, and which may have bumps or barbs for snapping behind the bar, or which may simply be bent down around the bar once it is in place.

Holders such as described above may also be provided on the wrap wire to secure it to the reinforcement bars. In addition these holders may be large enough to accommodate two reinforcement bars so that when a reinforcement basket must be made which is longer than the maximum available bar length, two bars can be inserted through a single holder to form an extra-length assembly.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a perspective view of a reinforcement basket according to this invention;

FIG. 2 is a large-scale view of a detail of FIG. 1;

FIGS. 3-5 are end views of holders according to this invention;

FIG. 6 is a perspective view of a holder according to this invention;

FIG. 7 is a side view showing how an over-long assembly can be made according to this invention;

FIG. 8 is a side view of the wrap-wire assembly according to this invention; and

FIG. 9 is an end view of a variant of the arrangement of FIG. 8.

SPECIFIC DESCRIPTION

As seen in FIGS. 1 and 2 a plurality of standard ridged steel reinforcement bars 1 extending parallel to a central axis A and to axially extending spacer wires 2 are surrounded by a helicoidal wire wrap 3 that is welded at 14 to the spacer wires 2. Hoops 4 of short cylindrical shape are secured via welds 14' to the holding wires 2 and via holders 5 to the bars 1. The entire assembly is generally cylindrical and centered on the axis A.

As seen in FIG. 2 these holders 5 are U-shaped and secured by means of welds 14" to the end edges 4' of the hoops 4. The outer leg of each holder 5 may be formed either with a barb 6 adjacent a weakened region 8, or with bumps 7. These barbs 6 or bumps 7 engage over the bar 1 to lock it in place. It is also within the scope of this invention to plastically deform the outer leg around the bar 1 after it is in place in the manner shown in FIG. 1.

FIG. 3 shows a holder 5a comprising a pair of upstanding pins 9 welded at 14" to the end edge 4' and delivered to the user standing radially up. Once the bar 1 is in place the outer ends of these pins 9 are bent over. FIG. 3 also shows how the bar 1 might be tubular.

In FIG. 4 a holder 5b is shown having a pair of upstanding pins 9' welded to the outer cylindrical face 4" of the hoop 4. These pins 9' have adjacent their outer ends inwardly directed bumps 10 and are formed inwardly therefrom with weakened regions or recesses 8 so that they can be deflected outwardly by the rod 1 when it is forced between them.

In FIG. 5 a holder 5c is formed as a simple U-shaped hoop or eye 12 which can be deformed plastically inwardly by striking in the direction shown by arrow 13 to tightly grip a bar 1. The legs of this U-shaped eye 12 are both welded to the end edge 4" of the hoop 4.

In FIG. 6 a flat metallic element 15 is welded once again to the other face 4" of the hoop 4 to constitute a holder 5d. The free end of this element 15 is hammered over as shown at 16 once the reinforcement rod 1 has been inserted through it.

FIG. 7 shows how an extra-long basket can be made by inserting two bars 1 through each of the holders 5. These holders 5 can then be clenched around the bars 1 so as to produce a basket having a length that can be substantially longer than that of the longest rod 1.

FIG. 9 shows how the wire wrap 3 is welded to the holding bars 2 and how these bars 2 are in turn welded at 14 to the hoops 4. This welding is possible because the material of the

elements

2, 3, and 4 is of a readily weldable steel, whereas the material of the bars 1 is not.

Finally, FIG. 9 shows a turn of the wire wrap 1 which is provided with the holder 5e constituted as a malleable iron wire having one end 17 wrapped tightly around the wire 3 and another end 18 forming a passage like the holder 5 of FIG. 1. This arrangement, therefore, allows the reinforcement bars 1 to be tightly secured also to the wrap wire 3.

The system according to the instant invention, therefore, allows a reinforcement basket to be fabricated on the job with relative ease. Nonweldable bars 1 can be used, yet the onerous process of securing them in place to the other weldable parts of the structure is eliminated by providing holders on the hoops 4 as well as if desired on the turns of the wire 3. The finished assembly is extremely rigid so that it can be handled by a crane without fear of its deforming or coming apart.

Claims

I claim:

1. A reinforced-concrete column reinforcement comprising:

two generally cylindrical weldable-steel complete hoops centered on and spaced apart along an axis and each having a generally cylindrical outer surface centered on the hoop axis;

a plurality of weldable-steel deformable holders welded at angular spacings on said hoops;

respective rigid longitudinal reinforcement bars each extending axially through a respective one of said holders of one of said hoops and through a respective one of said holders of the other of said hoops, said holders gripping said bars, holding said bars against said outer surfaces, and forming said bars and hoops into a rigid assembly; and

a helicoidal wrapping wire generally centered on said axis, fixed to said hoops, and surrounding said bars.

2. The reinforcement defined in claim 1, further comprising axially extending spacer rods fixed to said hoops and to said wrap wire and thereby fixing said wire to said hoops.

3. The reinforcement defined in claim 1 wherein each of said holders is forms an axially throughgoing passage through which the respective bar passes.

4. The reinforcement defined in claim 3 wherein each of said hoops has a pair of end edges lying in planes substantially perpendicular to said axis, said elements being secured to one of said end edges of the respective hoop.

5. The reinforcement defined in claim 3 wherein said elements are welded to said cylindrical outer surfaces.

6. The reinforcement defined in claim 3 wherein each of said holders comprises two such elements bent together over the respective bar.

7. The reinforcement defined in claim 3 wherein each of said elements is bent into an annular eye shape.

8. The reinforcement defined in claim 1, further comprising further such holders securing said bars to said wrap wire.

9. The reinforcement defined in claim 1 wherein said wire is of a weldable steel and said bars are of a nonweldable steel.

10. The reinforcement defined in claim 1 wherein said bars are tubular.

11. The reinforcement defined in claim 1 wherein each of said holders is sufficiently large to receive two such bars.